Sulfides, organic tests

The presence of chloride, nitrate, sulfide, organic sulfonates, cyanates, organic amines, and particulate matters may interfere in the test. The two major interferences, chloride and nitrate, however, may be removed in the acid backwash steps. Sulfide reacts with methylene blue to form a colorless complex. Interference from sulfide may be removed by treating the sample with a few drops of 30% H2Oz, whereupon sulfide converted into sulfate. 

In New York and Massachusetts where PCB contamination is always a possibility, the laboratory tests required by the state environmental protection agencies for analysis of a petroleum-contaminated soil are as follows (a) flash point (b) total petroleum hydrocarbon (TPH) (c) PCB screening (d) total organic halides (TOH) (e) reactivity of cyanide and sulfide (f) BTEX or equivalent (g) eight metals under TCLP (Toxicity Characteristics Leaching Procedure) for USTs and (h) full range of tests under TCLP for ASTs and spills. 

Table VII gives the m.p. of other alumohalides and their mixed systems. For example, low-melting electrolytes based on AlCla MCl chloraluminates, where M is Li, Na, K, have been considered (87), and cells with A1 anode and various cathodes, both inorganic and organic, were tested. The sulfur cathode seems to be the most suitable, although complex chlorides, fluorides and sulfides show possibilities. An experimental Al/S cell is described in detail in (88). The reaction 2A1 + 3S = AI2S3 provides a TED of 1275 Wh/kg at 200°. It is viewed only as a primary battery, however at the present time (88).

Copper and copper-containing alloys are susceptible to attack by elemental sulfur and hydrogen sulfide as well as organically bound sulfur. Active or elemental sulfur and hydrogen sulfide gas can attack copper to form copper sulfide, a dark-brown to black compound. This can be seen through ASTM D-130 copper corrosion testing. 

The corrosion behavior tends to follow much the same pattern in clean sea water the world over. If there is pollution, it may cause an unbalance of the pH, change the marine organism concentration, decrease the dissolved oxygen, or alter the ionic balance of sea water. Pollution normally results in saline waters becoming considerably more aggressive to one or more metals. Specific tests must be made to determine the applicability of a metal in each type of polluted water. Sulfides, which are often found m such waters, tend to promote corrosion of both ferrous and nonferrous metals. 

Oxidation with hydrogen peroxide is very popular in pharmaceutical development as a test for oxidative conditions55 (42). The most common reactions with organic compounds are electrophilic attack on amines and sulfides to give N-oxides and sulfoxides or sulfones, respectively, and the slower attack on carbon-carbon double bonds to give epoxides. These reaction are ionic and do not involve radicals ... 

Although hydrogen sulfide production via putrefaction correlated strongly with numbers of proteolytic bacteria (r=0.94,0.86), none was found for protein (r=0.16) or organic carbon (r=034) in Third Sister Lake. The significance of this is not known due to the many associated uncertainties, but it seems reasonable to assume that protein input would result in enhanced hydrogen sulfide production via putrefaction. Results of experiments to test this in laboratory bioreactor studies indicated that protein (egg albumin) added at the rate of approximately 20 ppm d 1 increased the population of putrefying bacteria by 90 percent and the rate of sulfide production via putrefaction by... 

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